Anchoring structure



Aug. 2, 1966 H. J. STIMSON 3,263,541

ANCHORING STRUCTURE Filed Sept. 15 L964 5 SheetsSneet 1 FIG. 9 BY Aug. 2, 1966 H. J. STIMSON ANCHORING STRUCTURE 5 Sheets-Sneet 2 Filed Sept. 15. 1964 I NVENTOR.

H.J. STIMSON BY w FIG. 3

Aug. 1966 H. J STlMSON 3,263,641

ANCHORI NG STRUCTURE Filed Septl5, 1964 5 Sheets-Sheet 5 1? 32 FIG. 6 h INVENTOR.

H.J. STIMSON BY Way 3,263,641 ANCHORING STRUCTURE Homer J. Stimson, Houston, Tex., assignor of one-third to Robert F. Patterson, Houston, Tex., and one-third to Don Kahle, Salthurn by the Sea, Yorkshire, England Filed Sept. 15, 1964, Ser. No. 396,558 9 Claims. (Cl. 114-'206) The present invention relates to anchoring structure and more particularly to anchor structure suitable for maintaining drilling and oil-producing equipment in a fixed relation to the bottom of a body of water, such as the coastal regions.

Heretofore various expedients have been used for anchoring and many of them depended upon a hook extending into the mud or the bottom or due to the weight of a large mass. However, it was difficult to position such large masses in the precise position and the amount of maintaining drilling and oil-producing equipment in a pensive and difficult to manipulate.

An object of the present invention is to provide an anchoring structure which can be readily placed in position with relatively light anchor handling equipment and can thereafter be secured to the bottom by the effective pressure of the water on the anchoring structure.

Another object of the invention is to provide a hollow anchor structure which effectively seals against the bottom of a body of water to produce a substantial difference in pressure within the anchor structure and the pressure of the water adjacent thereto.

A further object is to a provide an anchor structure which can be released from the bottom at will and be reused at a new location.

Other and further objects will be apparent as the description proceeds and upon reference to the accompanying drawings, wherein:

FIGURE 1 is a vertical section through an anchor structure made according to the present invention including an open bottom hollow cylindrical compartment and a conical closed compartment thereabove, with valve means communicating between the cylindrical compartment and the conical compartment and other valve means providing communication from the conical compartment to the adjacent body of water.

FIGURE 2 is a section taken along broken line 2-2 of FIGURE 1, with some of the bracing omitted for simplicity.

FIGURE 3 is a bottom plan view of a modified anchor in the form of a mat having a number of separate open bottom compartments communicating with closed upper compartments with the compartments being generally box shaped.

FIGURE 4 is a vertical section through one portion of the mat arrangement of box-like compartments, taken substantially on line 44 of FIGURE 3.

FIGURE 5 is an enlarged fragmentary section taken substantially on line 55 of FIGURE 3, showing the valve arrangement between the closed compartment and the exterior.

FIGURE 6 is a fragmentary section taken on line 66 of FIGURE 3, showing the valve arrangement providing communication between the open bottom compartment and the closed upper compartment.

FIGURE 7 is a vertical section similar to FIGURE 1 showing a plurality of closed compartments with rupture disc means between each closed compartment and the open bottom compartment with plunger means for rupturing the discs as the material in the bottom of the body of water presses against the bottom ends of the plungers with plug means closing openings between each closed compartment and the exterior with the plungers United States Patent 3,263,641 Patented August 2, 1966 and plugs shown in a single plane for the purpose .of illustration.

FIGURE 8 is a horizontal section taken substantially on line .88 of FIGURE 7 showing the plungers in equally spaced circumferential and radial relation.

FIGURE 9 is a fragmentary section showing a sealing gasket means for the bottom edge of the open bottom compartment.

Briefly, the present invention provides a method and ananchoring structure which includes one or more hollow fluid-tight compartments having communicating means with an open bottom compartment immediately therebelow with valve means to control the flow of fluid from the open bottom compartment to the one or more closed fluid-tight compartments and other means providing communication between each closed compartment and the exterior. The anchor is provided with supporting means to lower the anchoring structure and the bottom edge of the bottom compartment sinks into the bottom of the ocean or other body of water providing a fluidtight seal and thereafter the valve or other fluid control means provides access for the high pressure in the fluid in the open bottom compartment and one of the closed fluid-tight compartments, thereby reducing the pressure in the open bottom compartment resulting in the hydrostatic pressure at the bottom of the ocean pressing the anchoring structure securely against the ocean bottom. When it is desiredto release the anchoring structure from the bottom, the valve means between the closed compartment communicating with the open bottom compartment is operated by remote control to equalize the pressure within the anchor structure and the pressure of the water in the bottom of the ocean, thereby making it possible to remove the anchor by a relatively small force corresponding to the weight of the materials of which the anchor structure is composed.

Upon more detailed reference to the drawings, the anchor structure includes a generally cylindrical open bottom fluid-tight compartment having a cylindrical wall 10, a top wall 11 secured thereto intermediate the top and bottomwith ballast material 12 above the top 11, with the ballast material being lead, concrete, reinforced concrete, and the like, and on top of the ballast material and secured to the open bottom compartment is a closed fluid-tight compartment including a conical wall section 13, a curved wall section 14, and a bottom wall section 15 forming a fluid-tight closed compartment which is braced by suitable bracing 16 to withstand the pressures at the bottom of the body of water. A pipe 17 provides communication to a first valve 18 from the open bottom compartment 10 while a pipe section 1.9 extends into the fluid-tight closed compartment. The valve 18, a motor 20 for operating the valve, and a remote control device 21 are sealed in a housing 22 to prevent liquid and the like from contacting the control equipment, whereby the valve 18 may be opened and closed by the motor 20 in response to the control device 21 which may be a radio or an acoustical responsive control device, or the like, whereby the user of the anchor can selectively open or close the valve 18 to provide the communication between compartment 10 and the fluid-tight closed compartment 13.

Other means including a pipe 23, a second valve 24, a pipe section 25, a motor 26 for operating the valve 24, a motor control device 27 and a housing 28 correspond to items 17 to 22, inclusive previously described and this second valve structure 24 provides communication between the closed compartment 13 and the body of water when desired.

The bottom edge of the open bottom compartment 10 is shown as having a relatively sharp edge which will sink 3 into the mud bottom 29 and provide a fluid-tight seal between the open bottom compartment and the bottom of the ocean preventing the pressure of the water of the ocean reaching a high value within the open bottom compartment 10. Thereafter the valve 18 is opened and the air within the compartment 13 is compressed by whatever pressure exists within the open bottom compartment 10 until a balanced condition occurs in which the pressure in the open bottom compartment 10 and the communicating conical compartment 13 are equalized and are substantially less than the pressure at the bottom of the ocean, resulting inan effective downward force of the pressure of the water in the ocean on the anchor retaining the anchor effectively against the bottom.

When it is desired to remove the anchor, the valve 24 is opened by the remote control device 27 and the motor 26 permitting the pressure of the ocean to pass into the chamber 13 thereby balancing the pressure within chamber 13 and the open bottom compartment 10 permitting the anchor to be lifted by a force corresponding to the weight of the materials of the anchor.

Upon reference to FIGURES 3 to 6, inclusive, a mat anchor structure is provided :by means of box-like compartments in which twelve open bottom compartments are shown in plan in FIGURE 3, with twelve fluid-tight closed compartments immediately thereabove and the description will be made of one unit shown in the upper left-hand corner of FIGURE 3 as the other units are substantially identical.

An open bottom compartment includes longitudinal walls 30, 30 and transverse walls 31, 31 with a top wall 32 over which ballast material 33 is positioned and a closed compartment is formed by a wall 34, a top wall 35 and transverse walls 31, 3-1 and longitudinal walls 30, 30.

Communication is provided between the open bottom compartment and the fluid-tight closed compartment thereabove by the same structure including pipe 17, valve 18, pipe section 19, motor and remote control structure 21 which are housed in housing 22, whereby the open bottom compartment and the closed compartment immediately thereabove can be placed in communication.

Similarly, communication is provided between the closed fluid-tight compartment and the exterior by items 23 to 28, inclusive, previously described, and each unit consisting of the open bottom compartment and the fluidtight closed compartment immediately thereabove are used in substantially the same manner as previously described, thereby increasing the eifectiveness by the increased size of the mat shown as being formed of twelve 1 units, for example.

Upon reference to FIGURES 7 and 8, the open bottom compartment is shown to include the cylindrical wall 10, the top wall 11, the ballast 12 on the top of which is positioned the modified form of structure which includes a conical shaped wall 36, a rounded wall portion 37 and a bottom wall portion 38 with horizontally extending walls 39 and 40 providing three separate fluid-tight compart ments with each compartment communicating with the open bottom compartment by a corresponding tube 40A, 39A, and 38A, with each tube being closed by a suitable rupture disc 41 which lies in the path of a corresponding plunger 40B, 39B, and 38B which plungers are guided by pistons 42 having apertures therethroug-h for the passage of liquid and guided at their bottoms by guides 43, also having apertures for the passage of liquid. Each plunger has a foot 40C, 39C and 38C which are adapted to engage the mud or the other fluid material of a solid nature which extends up into the open bottom compartment as the anchor strikes the bottom, whereby the corresponding plunger extends upwardly and punctures the diaphragm or disc permitting the passage of the fluid pressure from the open bottom compartment to the corresponding fluid-tight closed compartment. If the anchor extends deeply into the solid material in the bottom of the ocean, all of the feet would be engaged and the pressure would be distributed in all of the compartments above the walls 38, 39 and 40, respectively.

When it is desired to lift the anchor by the anchor chain 50, the plugs D, 39D and 38D are removed from the compartment in communication with the open bottom compartment 10, thereby providing the pressure of the liquid on the material of the ocean bottom within the open bottom compartment 10, permitting the removal of the anchor by hoisting on the chain with a force in the order of the weight of the materials of which the anchor was originally made.

The plugs are removed by suitable cables as shown or other suitable means may be provided for the purpose.

The bottom guide 43 for each plunger is preferably fixed in position and the plunger moves vertically therethrough while the piston 42 at the top of each plunger is preferably fixed to the plunger and slidable in the tube surrounding it. Suitable stops may be provided to limit the vertical movement of the plungers such as stops 51 as shown fixed to the plunger and abutting the bottom guide 43.

It will be apparent that changes may be made within the spirit of the invention as defined by the valid scope of the appended claims.

What is claimed is:

1. An anchoring structure comprising a hollow fluidtight structure having at least one fluid-tight compartment and an open bottom compartment, sufficient ballast in said structure to sink said structure in a body of liquid when the compartments are empty, means to provide a fluidtight seal between the open bottom of said open bottom compartment and the bottom of said body of liquid, means selectively providing communication between said open bottom compartment and said at least one fluid-tight compartment whereby the fluid in the open bottom compartment may pass into said at least one fluid-tight compartment thereby reducing the pressure within said open bottom compartment whereby the column of liquid above said anchor structure will apply a holding force on said anchor against the bottom of said body of liquid eflective- 1y maintaining said anchor on the bottom of said body of liquid.

2. The invention according to claim 1 in which other means selectively provide communication between said at least one fluid-tight compartment and said body of liquid.

3. The invention according to claim 1 in which the structure includes a plurality of fluid-tight compartments and means selectively providing communication between each fluid-tight compartment and said open bottom compartment.

4. Anchor structure comprising an upstanding hollow generally cylindrical compartment having an open bottom and a closed top, a bell-shaped structure extending upwardly from said closed top, selective communication means between said open bottom compartment and said bellshaped compartment including a first valve means and first remote control means for said first valve means, and selectivecommunication means between said bell-shaped compartment and the said exterior including a second valve means and second remote control means for operating said second valve means.

5. Anchor means comprising a plurality of generally cubical compartments having fluid-tight walls therebetween, open bottom fluid-tight compartments immediately beneath said cubical compartments and having means along the bottom edge of the Walls of each open bottom compartment to fluid tightly seal with the bottom of a body of water, valve means between each cubical compartment and an open bottom compartment therebeneath, and remote control means to operate said valve means.

6. Anchor structure comprising an upstanding hollow compartment having an open bottom, with a closed top, a closed compartment structure extending upwardly from said closed top, communication means between said open bottom compartment and said closed compartment including rupture discs in said communication means, and plunger means extending into the open bottom compartment and engagable with the material extending into the open bottom compartment to be moved by such material in a direct ion to rupture the rupture disc.

7. The invention according to claim 6 in which an aperture extends through said closed compartment and a plug closes said aperture, and means to remove said plug.

8. The invention according to claim 7 in which the structure includes a plurality of closed compartments and communication means, rupture discs, apertures and plungers provided for each closed compartment.

9. A method of securing an anchoring structure to the bottom of a body of liquid comprising providing a hollow fluid-tight structure with a plurality of closed fluid-tight compartments and an open bottom fluid-tight compartment with sufficient ballast to sink in the body of liquid when the compartments are empty, sinking the hollow structure with its open bottom compartment in fluid-tight association with the bottom of the body of liquid providing thereby a closed fluid-tight compartment of said open bottom compartment, providing communication between said open bottom compartment and at least one of said fluid-tight compartments whereby part of the fluid in the closed fluid-tight open bottom compartment passes into said at least one fluid-tight compartment so the pressure within said communicating closed fluid-tight open bottom compartment and said at least one compartment becomes less than the liquid pressure at the bottom of the body of liquid whereby the column of liquid above said anchor structure will apply a holding force on said anchor equal to the difference between the pressure in said closed fluidtight compartment and said liquid pressure at the bottom of said body of liquid.

References Cited by the Examiner UNITED STATES PATENTS 1,758,911 5/1930 Hamilton ll4206 2,938,353 5/1960 Vorenkamp 6l-46.5 3,051,117 8/1962 Hunter 1l4-206 MILTON BUCHLER, Primary Examiner.

T. M. BLIX, Assistant Examiner. 

1. AN ANCHORING STRUCTURE COMPRISING A HOLLOW FLUIDTIGHT STRUCTURE HAVING AT LEAST ONE FLUID-TIGHT COMPARTMENT AND AN OPEN BOTTOM COMPARTMENT, SUFFICIENT BALLAST IN SAID STRUCTURE TO SINK SAID STRUCTURE IN A BODY OF LIQUID WHEN THE COMPARTMENTS ARE EMPTY, MEANS TO PROVIDE A FLUID-TIGHT SEAL BETWEEN THE OPEN BOTTOM OF SAID OPEN BOTTOM COMPARTMENT AND THE BOTTOM OF SAID BODY OF LIQUID, MEANS SELECTIVELY PROVIDING COMMUNICATION BETWEEN SAID OPEN BOTTOM COMPARTMENT AND SAID AT LEAST ONE FLUID-TIGHT COMPARTMENT WHEREBY THE FLUID IN THE OPEN BOTTOM COMPARTMENT MAY PASS INTO SAID AT LEAST ONE FLUID-TIGHT COMPARTMENT THEREBY REDUCING THE PRESSURE WITHIN SAID OPEN BOTTOM COMPARTMENT WHEREBY THE COLUMN OF LIQUID ABOVE SAID ANCHOR STRUCTURE WILL APPLY A HOLDING FORCE ON SAID ANCHOR AGAINST THE BOTTOM OF SAID BODY OF LIQUID EFFECTIVELY MAINTAINING SAID ANCHOR ON THE BOTTOM OF SAID BODY OF LIQUID. 